The process of extracting common characteristics from two or more classes and combining them into a generalized superclass, is called Generalization. The common characteristics can be attributes or methods. Generalization is represented by a triangle followed by a line.
Specialization is the reverse process of Generalization means creating new sub classes from an existing class.
Let’s take an example of Bank Account; A Bank Account is of two types – Current Account and Saving Account. Current Account and Saving Account inherits the common/ generalized properties like Account Number, Account Balance etc. from a Bank Account and also have their own specialized properties like interest rate etc.